The present invention relates to a system and method for providing data stream protection useful in telecommunications systems. A Broadband Wireless Access (“BWA”) network in a given service area may consist of one or more cells. Within a cell, several sectors can be deployed using sectored antennas at a base station to increase the overall number of subscribers. A point of presence (“POP”) for service providers in the BWA network can be located distantly from the base station, e.g. at a central office or a head end, or co-located with the base station. Interconnection between the head end and the base station can be done via numerous methods such as using fiber-optic cable or via high capacity microwave radio in linear, ring, or star configurations.
In a BWA system, high speed data is connected to the base station to be distributed to all the remote stations, e.g. subscribers, such as via a network interface unit which can provide access to the high speed data. Incoming data can use various physical interfaces, such as OC-3, STM-1, DS3, E3, 10/100 Base-T, 1000 Gigabit Ether net, and others. The data is then distributed to individual circuits that process the data belonging to the remote stations associated with the particular sectors. These circuits may contain processors, media access control circuits, modems, and the like.
Each of these circuits is connected to a transceiver which contains all the radio frequency (“IF”) circuits. In turn, the transceiver is connected to a sector antenna that will serve remote stations within each covered area. The transceiver is preferably installed outdoor very close to the antenna to minimize loss through antenna feeder cable. As a general rule in data networks, communications pathways such as transceivers and modems are paired, with one modem being accessed by one specific transceiver at a time. Each such pair typically services a single sector.
The base station usually contains also one or more controller circuits that direct the data to appropriate locations. These controller circuits also monitor the status of the BWA system and generate or recognize an alarm when it occurs. Where equipment is redundantly protected, controller circuits may also make a decision to switch the data from a faulty piece of equipment to a standby one.
As also occurs from time to time, one or both components of transceiver/modem pairs will go into an alarm state, e.g. a failure or other degradation state that may impact on the ability of that pair to adequately and accurately provide data to and from the sector. In many cases, the BWA operators have to guarantee very high availability to the subscribers. Thus, there is a need to provide redundancy protection against hardware failure. This protection needs to be automatically triggered to minimize the down time.
The simplest way for redundant protection is to double every hardware component. However this is very costly, increases power consumption, and requires additional space to accommodate the additional circuits. Hence, there is a need for a scheme that provides very high availability with fewer circuits, such as providing one-for-one protection for certain circuits and one-for-many protection for other circuits.